The first time I ever came was with a pool raft when I was about 12. i remember just laying on it and rocking my hips back and forth and started getting hard and about a minute later I came. I wasn't sure what just happend but I knew it felt good. So that's what got me into inflatables.
I have a sprinkler ball, too. I used it in front of a couple of friends, and one wanted to go into the other end while I was still going at it--I let him and he came in 5 thrusts. He moaned like this and it made me come! After I came the other remaining guy entered where I was and gave 7 powerful, intense thrusts, ending with a huge ejaculatory stab into the sleeve and came for about 30 seconds while moaning! Those guys said they never came that hard in a girl! Shows how good vinyl and leather can feel!